A battery protection board, a battery system and a mobile device

Abstract

The application discloses a battery protection board, a battery system and a mobile device. The battery protection board comprises a power meter chip, a current sampling circuit and a first protection circuit. The first end and the second end of the power meter chip are connected with the positive electrode and the negative electrode of a battery pack respectively. The power meter chip is used for measuring the actual voltage of the battery pack. The current sampling circuit is used for collecting the charging current of the battery pack and feeding back to the power meter chip. The first protection circuit is used for protecting the battery pack according to the actual voltage and the charging current of the battery pack. The power meter chip is used for sending the actual voltage of the battery pack and the charging current of the battery pack to a mainboard system, so that the mainboard system charges the battery pack according to the actual voltage and the charging current of the battery pack. The actual voltage of the battery pack can be measured more accurately. Since the mainboard system controls the charging current according to the difference between the actual output voltage of the charging chip and the actual voltage of the battery pack, the charging efficiency is high when the charging current is large.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, specifically to a battery protection board, a battery system, and a mobile device. Background Technology

[0002] Currently, mobile devices (such as mobile phones, tablets, smart bracelets, etc.) all use lithium batteries. The battery protection board inside the battery pack is a core component, and its main function is to protect the battery during charging and discharging.

[0003] Battery charging often employs fast charging mode, typically to increase charging current and shorten charging time. However, due to the influence of the internal resistance of the battery protection board and related connectors, there is a significant voltage drop during charging and discharging, resulting in an error between the detected voltage on the mobile device and the actual output voltage of the battery cell.

[0004] Currently, mobile devices cannot accurately detect the actual output voltage of the battery pack, which reduces the actual charging capacity used. Summary of the Invention

[0005] In view of this, this application provides a battery protection board, a battery system, and a mobile device that can accurately detect the actual output voltage of the battery pack, thereby enabling better control of charging and improving charging efficiency.

[0006] This application provides a battery protection board, including: a fuel gauge chip, a current sampling circuit, and a first protection circuit;

[0007] The first and second terminals of the fuel gauge chip are connected to the positive and negative terminals of the battery pack, respectively.

[0008] The fuel gauge chip is used to measure the actual voltage of the battery pack;

[0009] The current sampling circuit is used to collect the charging current of the battery pack and feed it back to the fuel gauge chip;

[0010] The first protection circuit is used to protect the battery pack based on the actual voltage and charging current of the battery pack.

[0011] The fuel gauge chip is used to send the actual voltage and charging current of the battery pack to the motherboard system, so that the motherboard system can charge the battery pack according to the actual voltage and charging current.

[0012] Preferably, the battery pack includes two cells connected in parallel: a first cell and a second cell;

[0013] The first end of the fuel gauge chip is connected to the positive terminal of the first battery cell, and the second end of the fuel gauge chip is connected to the negative terminal of the second battery cell.

[0014] or,

[0015] The first end of the fuel gauge chip is connected to the positive terminal of the second battery cell, and the second end of the fuel gauge chip is connected to the negative terminal of the first battery cell.

[0016] Preferably, the first protection circuit includes a first protection chip and a protection switch transistor;

[0017] The protection switch is connected in series between the negative terminal of the battery pack and the negative terminal of the motherboard system;

[0018] The first protection chip is used to control the operation of the protection switch based on the actual voltage of the battery pack.

[0019] Preferably, it further includes: a second protection circuit;

[0020] The second protection circuit includes: a second protection chip, a protection switch, and a fuse;

[0021] The protection switch is connected to the fuse; the fuse is connected in series between the positive terminal of the battery pack and the positive terminal of the mainboard system.

[0022] The second protection chip is used to cut off the power supply circuit of the fuse by controlling the action of the protection switch based on the actual voltage of the battery pack.

[0023] Preferably, the current sampling circuit is a sampling resistor;

[0024] The sampling resistor is connected in series between the negative terminal of the battery pack and the negative terminal of the motherboard system.

[0025] Preferably, it further includes: a temperature sensor;

[0026] A temperature sensor is used to collect the temperature of the battery protection board and feed it back to the fuel gauge chip.

[0027] Preferably, the connection between the fuel gauge chip and the first and second battery cells adopts a centrally symmetrical wiring connection.

[0028] This application also provides a battery system, including: the battery protection board described above, and a motherboard system; the motherboard system includes a charging chip;

[0029] The positive and negative output terminals of the battery protection board are connected to the positive and negative terminals of the charging chip, respectively.

[0030] The charging chip is used to charge the battery pack based on the output voltage of the charging chip and the actual voltage of the battery pack.

[0031] Preferably, the charging chip controls the magnitude of the charging current based on the ratio of the difference between the output voltage of the charging chip and the actual voltage of the battery pack to the line impedance.

[0032] This application also provides a mobile device, including: the battery system described above, and a battery pack consisting of at least two cells connected in parallel.

[0033] Therefore, this application has the following beneficial effects:

[0034] The battery protection board provided in this application includes a fuel gauge chip, a current sampling circuit, and a first protection circuit. The fuel gauge chip is connected between the positive and negative terminals of the battery pack, which can avoid voltage drop caused by the internal resistance of the battery protection board and related connectors, and can obtain the actual voltage of the battery pack more accurately. The current sampling circuit feeds back the collected charging current of the battery pack to the fuel gauge chip. The fuel gauge chip feeds back the actual voltage and charging current of the battery pack to the mainboard system, so that the mainboard system controls the charging of the battery pack. The first protection circuit protects the battery pack according to the actual voltage and charging current of the battery pack. The battery protection board provided in this application can more accurately measure the actual voltage of the battery pack. Since the motherboard system controls the charging current based on the difference between the actual output voltage of the charging chip and the actual voltage of the battery pack, a larger charging current results in higher charging efficiency. To ensure safety, the motherboard system needs to ensure that the actual voltage of the battery pack is always lower than the maximum allowable voltage of the battery pack. To improve the utilization rate of the battery pack capacity, the motherboard system needs to control the actual voltage of the battery pack as close as possible to the maximum allowable voltage of the battery pack. Therefore, by obtaining a more accurate actual voltage of the battery pack, the battery protection board enables the motherboard system to more accurately control the charging of the battery pack, improve charging efficiency, ensure safety, and improve the utilization rate of the battery pack capacity. Attached Figure Description

[0035] Figure 1 A schematic diagram of a battery protection board provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram illustrating the connection method of a fuel gauge chip provided in an embodiment of this application;

[0037] Figure 3 A schematic diagram of another battery protection board provided in an embodiment of this application;

[0038] Figure 4 A schematic diagram of a battery system provided in an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of a terminal device provided in an embodiment of this application. Detailed Implementation

[0040] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0041] See Figure 1 The figure is a schematic diagram of a battery protection board provided in an embodiment of this application.

[0042] The battery protection board provided in this application embodiment includes: a fuel gauge chip 100, a current sampling circuit 200, and a first protection circuit 300.

[0043] To enable those skilled in the art to better understand the technical solutions provided in this application, the principle of battery charging is briefly explained below.

[0044] On the battery protection board, the fuel gauge chip 100 feeds back the detected battery pack voltage and charging current information to the motherboard system. The motherboard system adjusts the charging current and maximum output voltage of the charging chip based on the battery pack voltage and charging current information.

[0045] During the charging process, the parameters conform to the following formula:

[0046] Ibat = (Vout - Vbat) / Rbat

[0047] In the formula, Vout is the actual output voltage of the charging chip, Vbat is the actual voltage of the battery pack, Rbat is the line impedance from the output terminal of the charging chip to the battery pack, and Ibat is the actual charging current.

[0048] To ensure battery charging safety, the maximum output voltage VOUT of the charging chip is generally not allowed to exceed the maximum allowable voltage VBAT of the battery pack; otherwise, there will be an overvoltage risk. As the formula shows, with constant impedance, the actual charging current will continuously decrease as the actual voltage of the battery pack increases.

[0049] In fast charging mode, in order to improve charging efficiency, the motherboard system allows the maximum output voltage VOUT of the charging chip to rise above the maximum voltage VBAT allowed by the battery pack, but at the same time, it must ensure that the actual voltage Vbat of the battery pack is always lower than the maximum voltage VBAT allowed by the battery pack.

[0050] The control method for fast charging mode requires real-time monitoring of the actual battery pack voltage Vbat and feedback to the motherboard system to ensure a large Vout-Vbat value, thereby maintaining a large actual charging current Ibat. Simultaneously, it must ensure that the actual battery pack voltage Vbat is as close as possible to the maximum allowable voltage VBAT of the battery pack to improve battery capacity utilization. Therefore, the fuel gauge chip 100 needs to perform high-precision monitoring and feedback of the actual battery pack voltage Vbat.

[0051] The technical solution provided in this application embodiment involves connecting the first and second terminals of the fuel gauge chip 100 to the positive terminal B+ and the negative terminal B- of the battery pack, respectively; the battery pack includes at least two cells connected in parallel. For ease of explanation, this application embodiment uses the example of a battery pack containing two cells connected in parallel, i.e., the first cell and the second cell are connected in parallel. However, the battery pack may also include more cells, which is not limited here.

[0052] The fuel gauge chip 100 is used to measure the actual voltage of the battery pack.

[0053] Traditional technology typically measures the actual voltage of the battery pack at the positive terminal P+ and the negative terminal P- of the motherboard system. However, in fast charging mode, the charging current is large, and the actual voltage of the battery pack is measured to be lower due to the internal resistance of the battery protection board and related connectors, resulting in low charging efficiency.

[0054] The first and second terminals of the fuel gauge chip 100 are connected to the positive terminal B+ and the negative terminal B- of the battery pack, respectively. This avoids voltage drop caused by the internal resistance of the battery protection board and related connectors, making the measured actual voltage of the battery pack more accurate and improving charging efficiency.

[0055] The current sampling circuit 200 is used to collect the charging current of the battery pack and feed it back to the fuel gauge chip 100.

[0056] The first protection circuit 300 is used to protect the battery pack based on the actual voltage and charging current of the battery pack.

[0057] Based on the actual voltage and charging current of the battery pack, the first protection circuit 300 can determine whether a fault has occurred. When a fault occurs, the first protection circuit 300 cuts off the circuit, thereby protecting the battery pack. Faults include, but are not limited to, overvoltage, overcurrent, undervoltage, or short circuit.

[0058] The fuel gauge chip 100 is used to send the actual voltage and charging current of the battery pack to the motherboard system, so that the motherboard system can charge the battery pack according to the actual voltage and charging current, i.e., adjust the charging current.

[0059] The battery protection board provided in this application includes a fuel gauge chip, a current sampling circuit, and a first protection circuit. The fuel gauge chip is connected to the positive and negative terminals of the battery pack, avoiding voltage drop caused by the internal resistance of the battery protection board and related connectors, resulting in a more accurate measurement of the actual battery pack voltage. The current sampling circuit feeds back the collected charging current of the battery pack to the fuel gauge chip. The fuel gauge chip feeds back the actual battery pack voltage and charging current to the motherboard system, enabling the motherboard system to control the battery pack charging. The first protection circuit protects the battery pack based on its actual voltage and charging current. The battery protection board provided in this application can more accurately measure the actual voltage of the battery pack, allowing the motherboard system to more accurately control charging, improve charging efficiency, and increase the utilization rate of the battery pack capacity.

[0060] The following section, with reference to the accompanying diagram, describes a specific connection method between a fuel gauge chip and a battery pack.

[0061] See Figure 2 The figure is a schematic diagram of the connection method between a fuel gauge chip and a battery pack provided in an embodiment of this application.

[0062] This embodiment takes a battery pack consisting of two cells connected in parallel as an example. The two cells are: the first cell and the second cell. Each connection between the two cells has a different resistance, namely R1, R2, R3, R4, R5 and R6.

[0063] The specific connection is as follows: the first end of the fuel gauge chip is connected to the positive terminal of the first battery cell, and the second end of the fuel gauge chip is connected to the negative terminal of the second battery cell.

[0064] During charging, the actual voltage of each cell should always be lower than the maximum allowable voltage of each cell.

[0065] If the first and second terminals of the fuel gauge chip are connected to the positive and negative terminals of a battery cell respectively, and the voltage of this battery cell is fed back to the motherboard system, the motherboard system will default to this voltage as the actual voltage of all battery cells. However, due to the resistance in the wiring, and the fact that R1+R2+R3≠R4+R5+R6, the actual voltage of the first and second battery cells will differ significantly when the current is the same. For example, the actual voltage of the first battery cell = the actual voltage of the second battery cell + the voltage drop across the six resistors. In this case, the actual voltage of the battery cell is inaccurate, which may result in the battery cell not being fully charged or the actual voltage exceeding the maximum allowable voltage of the battery cell.

[0066] Therefore, the first terminal of the fuel gauge chip is connected to the positive terminal of the first battery cell, and the second terminal is connected to the negative terminal of the second battery cell. This can reduce the difference in actual voltage between different battery cells to a certain extent. For example, the actual voltage of the first battery cell = the actual voltage of the second battery cell + the first voltage - the second voltage. This further makes the actual voltage of the battery cell measured by the fuel gauge more accurate, and improves the safety and accuracy of charging control. Here, the first voltage refers to the voltage divided by R1, R3, and R5, and the second voltage refers to the voltage divided by R2, R4, and R6.

[0067] Of course, the specific connection method of the fuel gauge chip can also be related to... Figure 2 The connection method is symmetrical, that is, the first end of the fuel gauge chip is connected to the positive terminal of the second battery cell, and the second end of the fuel gauge chip is connected to the negative terminal of the first battery cell. This can also achieve the purpose of reducing the actual voltage difference between different battery cells.

[0068] Specifically, the connection between the fuel gauge chip and the first and second battery cells can be achieved using a centrally symmetrical wiring connection. This application does not specifically limit the exact shape of the central symmetry; the aim is to reduce differences caused by wiring during fuel gauge chip sampling. For example, an S-shaped wiring can be used. Compared to the traditional C-shaped wiring, the S-shaped wiring is more symmetrical and can offset differences caused by wiring impedance.

[0069] The embodiments of this application adopt a centrally symmetrical connection method, with the first end of the fuel gauge chip connected to the positive terminal of the first battery cell and the second end of the fuel gauge chip connected to the negative terminal of the second battery cell; this can reduce the difference in actual voltage between different battery cells to a certain extent; further, it makes the actual voltage of the battery cell measured by the fuel gauge more accurate, and improves the safety and accuracy of charging control.

[0070] This application does not specifically limit the implementation of the current sampling circuit and the first protection circuit. The following describes a possible implementation with reference to the accompanying drawings.

[0071] See Figure 3 The figure is a schematic diagram of another battery protection board provided in an embodiment of this application.

[0072] The battery protection board provided in this application embodiment includes: a fuel gauge chip 100, a current sampling circuit 200, a first protection circuit 300, and a second protection circuit 400.

[0073] In this embodiment, the connection method and function of the fuel gauge chip 100 can be referred to in the above embodiments, and will not be repeated here.

[0074] The current sampling circuit 200 is a sampling resistor Rc; the sampling resistor Rc is connected in series between the negative terminal B- of the battery pack and the negative terminal P- of the motherboard system.

[0075] The first protection circuit 300 specifically includes a first protection chip 301 and a protection switch 302. The protection switch 302 is connected in series between the negative terminal B- of the battery pack and the negative terminal P- of the motherboard system. The first protection chip 301 is used to control the operation of the protection switch 302 according to the actual voltage of the battery pack. Specifically, when the battery pack experiences a fault such as overvoltage or undervoltage, the first protection chip 301 controls the protection switch 302 to disconnect, thereby protecting the battery pack.

[0076] The second protection circuit 400 specifically includes: a second protection chip 401, a protection switch 402, and a fuse 403.

[0077] The protective switch 402 is connected to the fuse 403; the fuse 403 is connected in series between the positive terminal B+ of the battery pack and the positive terminal P+ of the mainboard system; the second protection chip 401 is used to cut off the power supply circuit containing the fuse 403 by controlling the protective switch 402 according to the actual voltage of the battery pack. Specifically, when the battery pack experiences a fault such as reverse connection or short circuit, the fuse 403 will be tripped, thereby protecting the battery pack.

[0078] Adding a second protection circuit to the battery protection board can still disconnect the circuit in time when the battery pack fails and the first protection circuit also fails to act in time, thus improving the stability of the battery protection board and further protecting the battery pack.

[0079] The battery protection board provided in this application may also include a temperature sensor for collecting the temperature of the battery protection board and feeding it back to the fuel gauge chip; so that the motherboard system can simultaneously control charging based on the temperature of the battery pack protection board.

[0080] The battery protection board provided in this application embodiment can more accurately measure the actual voltage of the battery pack, and also collect the temperature of the battery protection board, so that the main board system can make more appropriate charging control; it also adds a second protection circuit to avoid the failure of the first protection circuit to cut off the circuit in time when it fails, thereby improving the stability of the battery protection board and protecting the battery pack more reliably.

[0081] Based on the battery protection board provided in the above embodiments, this application also provides a battery system, which will be described in detail below with reference to the accompanying drawings.

[0082] See Figure 4 The figure is a schematic diagram of a battery system provided in an embodiment of this application.

[0083] The battery system provided in this application embodiment includes, in addition to the battery protection board 1000 described in the above embodiment, a motherboard system 2000; wherein the motherboard system 2000 includes a charging chip 500.

[0084] The positive and negative output terminals of the battery protection board 1000 are connected to the positive and negative terminals of the charging chip 500, respectively.

[0085] The charging chip 500 is used to charge the battery pack based on the output voltage of the charging chip and the actual voltage of the battery pack.

[0086] Specifically, the charging chip 500 controls the charging current based on the ratio of the difference between the output voltage of the charging chip and the actual voltage of the battery pack to the line impedance. Detailed control procedures for the charging chip 500 can be found in the principle description of the above embodiments, and will not be repeated here.

[0087] The battery system provided in this application embodiment has a battery protection board that feeds back a more accurate actual voltage of the battery pack to the motherboard system. The charging chip in the motherboard system performs more accurate control based on the output voltage of the charging chip and the more accurate actual voltage of the battery pack, thereby charging the battery pack and improving charging efficiency.

[0088] Based on the battery protection board and battery system provided in the above embodiments, this application also provides a terminal device, which will be described in detail below with reference to the accompanying drawings.

[0089] See Figure 5 This figure is a schematic diagram of a mobile device provided in an embodiment of this application.

[0090] The mobile device provided in this application embodiment includes, in addition to the battery system 3000 described in the above embodiment, a battery pack 4000 composed of at least two cells connected in parallel.

[0091] In this embodiment, the composition and working principle of the battery system 3000 can be referred to the above embodiments, and will not be repeated here.

[0092] The mobile device provided in this application embodiment has a battery system that can more accurately control the charging of the battery pack, which can improve the charging efficiency of the mobile device, shorten the charging time, and increase the charging capacity of the battery pack; the battery system can also protect the safety of the battery pack.

[0093] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery protection board, characterized in that, include: Fusion meter chip, current sampling circuit, and first protection circuit; The first and second ends of the fuel gauge chip are respectively connected to the positive and negative terminals of the battery pack; The fuel gauge chip is used to measure the actual voltage of the battery pack; The current sampling circuit is used to collect the charging current of the battery pack and feed it back to the fuel gauge chip; The first protection circuit is used to protect the battery pack based on the actual voltage of the battery pack and the charging current; The fuel gauge chip is used to send the actual voltage and charging current of the battery pack to the motherboard system, so that the motherboard system can charge the battery pack according to the actual voltage and charging current; the battery pack includes the following two cells connected in parallel: a first cell and a second cell; The first end of the fuel gauge chip is connected to the positive terminal of the first battery cell, and the second end of the fuel gauge chip is connected to the negative terminal of the second battery cell; or, The first end of the fuel gauge chip is connected to the positive terminal of the second battery cell, and the second end of the fuel gauge chip is connected to the negative terminal of the first battery cell.

2. The battery protection board according to claim 1, characterized in that, The first protection circuit includes a first protection chip and a protection switch transistor; The protection switch is connected in series between the negative terminal of the battery pack and the negative terminal of the motherboard system; The first protection chip is used to control the operation of the protection switch based on the actual voltage of the battery pack.

3. The battery protection board according to claim 1 or 2, characterized in that, Also includes: Second protection circuit; The second protection circuit includes: a second protection chip, a protection switch, and a fuse; The protection switch is connected to the fuse; the fuse is connected in series between the positive terminal of the battery pack and the positive terminal of the motherboard system. The second protection chip is used to cut off the power supply circuit of the fuse by controlling the operation of the protection switch according to the actual voltage of the battery pack.

4. The battery protection board according to claim 1 or 2, characterized in that, The current sampling circuit is a sampling resistor; The sampling resistor is connected in series between the negative terminal of the battery pack and the negative terminal of the motherboard system.

5. The battery protection board according to claim 1 or 2, characterized in that, Also includes: Temperature sensor; The temperature sensor is used to collect the temperature of the battery protection board and feed it back to the fuel gauge chip.

6. The battery protection board according to claim 2, characterized in that, The connection between the fuel gauge chip and the first and second battery cells is a centrally symmetrical wiring connection.

7. A battery system, characterized in that, include: The battery protection board according to any one of claims 1-6 further includes a motherboard system; the motherboard system includes a charging chip; The positive and negative output terminals of the battery protection board are respectively connected to the positive and negative terminals of the charging chip. The charging chip is used to charge the battery pack according to the output voltage of the charging chip and the actual voltage of the battery pack.

8. The battery system according to claim 7, characterized in that, The charging chip specifically controls the magnitude of the charging current based on the ratio of the difference between the output voltage of the charging chip and the actual voltage of the battery pack to the line impedance.

9. A mobile device, characterized in that, include: The battery system of claim 7 or 8 further includes a battery pack consisting of at least two cells connected in parallel.

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